Localization behavior at bound Bi complex states in 
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Alberi, Kirstin; Christian, Theresa; Fluegel, B.; Crooker, S. A.; Beaton, Daniel A.; Mascarenhas, A.

doi:10.1103/physrevmaterials.1.024605

Cited by 5 publications

(5 citation statements)

References 31 publications

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“…As a matter of fact, our XPS characterization reveals the presence of different Bi configurations in our samples. The extent of the energy redshift is strongly dependent on the growth conditions that can give rise to the formation of different kinds of Bi-related complexes [28,31,33,35,36].…”

Section: Strain-dependent Photoluminescence Propertiesmentioning

confidence: 99%

Increasing Optical Efficiency in the Telecommunication Bands of Strain-Engineered Ga(As,Bi) Alloys

et al. 2020

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The search for semiconducting materials with improved optical properties relies on the possibility to manipulate the semiconductors band structure by using quantum confinement, strain effects, and by the addition of diluted amounts of impurity elements such as Bi. In this study, we explore the possibility to engineer the structural and physical properties of the Ga(As, Bi) alloy by employing different stress conditions in its epitaxial growth. Films with variable concentration of Bi are grown by molecular beam epitaxy on bare GaAs(001) crystals and on partially relaxed (In, Ga)As double buffer layers acting as stressors aiming to control the Bi incorporation into the alloy and improving the optical properties in terms of efficiency. A combination of several structural and electronic characterization techniques and dedicated density-functional-theory calculations allows us a systematic comparison between the samples grown under compressive and tensile strain. We demonstrate the possibility to grow Ga(As, Bi) under different strain conditions without affecting its crystal quality. The different strain conditions strongly impact the Bi incorporation in the GaAs matrix and the luminescence properties of the sample. We find (i) a striking improvement of the photoluminescence with a strongly increased radiative efficiency when Ga(As, Bi) is grown under tensile strain and (ii) an interesting higher redshift with respect to Ga(As, Bi) grown compressively on GaAs. These two effects allow us to reach the important photoluminescence emission at 1.3 µm with a Bi concentration as low as 4.9% compared to 7.5% needed for samples grown directly on GaAs. This is a significant achievement for the application of the Ga(As, Bi) material in optoelectronic devices.

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Section: Strain-dependent Photoluminescence Propertiesmentioning

confidence: 99%

Increasing Optical Efficiency in the Telecommunication Bands of Strain-Engineered Ga(As,Bi) Alloys

et al. 2020

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“…As discussed previously, GaAs (1−x) Bi x alloys tend to form localized pairs and clusters, which have different configurations and binding energies [3,6,66,76], alloy disorder, and potential fluctuation. These states are usually associated with two groups with different activation energies in undoped GaAs (1−x) Bi x samples: one ranges from 8 to 17 meV and is related to Bi clusters and Bi pairs [3,71,74,75], and the other energy around 50 meV is related to alloy disorder [69,75,77,78].…”

Section: Photoluminescencementioning

confidence: 79%

“…This indicates that higher density of non-radiative centers is present in p-GaAs 0.94 Bi 0.06 as compared to n-GaAs 0.94 Bi 0.06 sample. The non-radiative centers do not contribute to effectively change the band-gap energy in the electronic structure of the host lattice [65][66][67] but affects the optical efficiency.…”

Section: Photoluminescencementioning

confidence: 99%

Structural and optical properties of n-type and p-type GaAs_(1−x)Bi _x thin films grown by molecular beam epitaxy on (311)B GaAs substrates

Souza¹,

Alhassan²,

Alotaibi³

et al. 2021

Semicond. Sci. Technol.

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In this paper, we report on the structural and optical properties of n-type Si-doped and p-type Be-doped GaAs(1−x)Bix thin films grown by molecular beam epitaxy on (311)B GaAs substrates with nominal Bi content x=5.4%. Similar samples without Bi were also grown for comparison purposes (n-type GaAs and p-type GaAs). X-ray diffraction, micro-Raman at room temperature, and photoluminescence (PL) measurements as a function of temperature and laser excitation power (PEXC) were performed to investigate their structural and optical properties. X-ray diffraction results revealed that the Bi incorporation in both n-type and p-type doped GaAsBi was similar, despite that the samples present remarkable differences in the number of Bi related defects, non-radiative centers and alloy disorder. Particularly, our results evidence that the Birelated defects in n-and p-doped GaAsBi alloys have important impact on the differences of their optical properties.

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“…Photoluminescence properties. The photoluminescence properties of GaAsBi have been a subject of numerous studies 11,12,[53][54][55][56] . Notable PL features of the bismide include a broad PL peak at room temperature, a red-blue-red shift of the temperature-dependent PL peak-energy position, integrated PL intensity plateau at intermediate temperatures, and the saturation of the Stokes-shift at elevated excitation powers.…”

Section: Stem Image Analysis Of Gaasbi Anti-phase Domainsmentioning

confidence: 99%

“…The bandgap reduction occurs due to the interaction of resonant Bi and N states in the proximity of GaAs valence and conduction band edges (VBE, CBE), respectively. While individual Bi and N atoms produce bandgap bowing and potential fluctuations, stochastically incorporated pairs (Bi-Bi, N-N) or clusters are thought to be a source of the local density of states that lead to the pronounced charge carrier localization and scattering in these alloys [10][11][12][13] . The bismide has presently emerged as a more promising candidate for photovoltaics (PV) since the trap states are formed near its VBE, whereas they occur near CBE in the nitride.…”

mentioning

confidence: 99%

GaAs1-xBix growth on Ge: anti-phase domains, ordering, and exciton localization

Paulauskas

Pačebutas

Geižutis

et al. 2020

Sci Rep

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The dilute bismide alloy GaAs 1-x Bi x has drawn significant attention from researchers interested in its fundamental properties and the potential for infrared optoelectronics applications. To extend the study of bismides, molecular-beam heteroepitaxy of nominally 1.0 eV bandgap bismide on Ge substrates is comprehensively investigated. Analysis of atomic-resolution anti-phase domain (APD) images in the direct-epitaxy revealed a high-density of Ga vacancies and a reduced Bi content at their boundaries. This likely played a key role in the preferential dissolution of Bi atoms from the APD interiors and Bi spiking in Ge during thermal annealing. Introduction of GaAs buffer on offcut Ge largely suppressed the formation of APDs, producing high-quality bismide with single-variant CuPt B-type ordered domains as large as 200 nm. Atomic-resolution X-ray imaging showed that 2-dimensional Bi-rich (111) planes contain up to x = 9% Bi. The anomalously early onset of localization found in the temperaturedependent photoluminescence suggests enhanced interactions among Bi states, as compared to non-ordered samples. Growth of large-domain single-variant ordered GaAs 1-x Bi x films provides new prospects for detailed analysis of the structural modulation effects and may allow to further tailor properties of this alloy for optoelectronic applications.

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Localization behavior at bound Bi complex states in GaAs1−xBix

Cited by 5 publications

References 31 publications

Increasing Optical Efficiency in the Telecommunication Bands of Strain-Engineered Ga(As,Bi) Alloys

Increasing Optical Efficiency in the Telecommunication Bands of Strain-Engineered Ga(As,Bi) Alloys

Structural and optical properties of n-type and p-type GaAs_(1−x)Bi _x thin films grown by molecular beam epitaxy on (311)B GaAs substrates

GaAs1-xBix growth on Ge: anti-phase domains, ordering, and exciton localization

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Localization behavior at bound Bi complex states in GaAs1−xBix

Cited by 5 publications

References 31 publications

Increasing Optical Efficiency in the Telecommunication Bands of Strain-Engineered Ga(As,Bi) Alloys

Increasing Optical Efficiency in the Telecommunication Bands of Strain-Engineered Ga(As,Bi) Alloys

Structural and optical properties of n-type and p-type GaAs(1−x)Bi x thin films grown by molecular beam epitaxy on (311)B GaAs substrates

GaAs1-xBix growth on Ge: anti-phase domains, ordering, and exciton localization

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Product

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About

Structural and optical properties of n-type and p-type GaAs_(1−x)Bi _x thin films grown by molecular beam epitaxy on (311)B GaAs substrates